Catching remarks
Scomber colias is one of the most important commercial species throughout its habitat. It is fished mainly on the eastern side of the Atlantic (Bay of Biscay to South Africa) as well as in the Mediterranean, mostly in purse seine and pelagic trawl fisheries which target Sardina pilchardus and/or Engraulis engrasicolus. Often being bycatch (and then slipped), it may become the target species when it is highly available whereas sardine and anchovy are not. Another reason contributing to the recent rise in landings is the appearance of new markets (e.g., for tuna feeding). Tuna are among the natural predators together with swordfish, sharks, dolphins, and seals, so these risk becoming bycatch themselves when they are accidentally engulfed by the purse seine – just as other pelagic and semi- pelagic species may be accidentally caught.
The medium-sized pelagic S. colias may already suffer from injuries and stress when the purse seine is hauled close to the ship. Whether slipping of unwanted catch results in delayed mortality requires further research; discarding – once on board – is mostly done when the IND are dead and so should be avoided. Transfer to the storage space via scoop net potentially subjects wanted S. colias to further crowding, contact with the gear, lack of oxygen, and experience of its own weight. Storing most likely happens alive and without or with only little ice. And since death occurs most likely through asphyxia, the best would be pumping the IND on board and then immediately stun them followed by slaughter while still unconscious. Further research is needed for such a protocol.
For details see: WelfareCheck | catch (pre-release)
Related news
Our third WelfareCheck | catch is online – that of Scomber colias (Atlantic chub mackerel) caught with purse seines. Scomber colias often is second choice after Sardina pilchardus (European pilchard) or other small- and medium-sized pelagic species and then is even slipped for being unwanted. Yet, when these other species are scarce or it is prohibited to catch them, Scomber colias can become targeted to a high degree.
Maybe this situation of being second best in the eyes of fishing folks is the reason we could hardly find research on welfare for this species during the catching process. It nevertheless became clear during the literature search that the species potentially suffers already during hauling the purse seine and then especially after scooping it out. Recommendations how to improve the situation are urgently needed, probably involving immediate stunning once on deck followed by slaughter while still unconscious. If you have more information for us, please let us know!